Thanks Barry. 

My helpers are my grandchildren for whom I built the railroad for.  We saw a great garden railroad at Clark Gardens in Mineral Wells, TX a year ago, and decided to use the area behind the pool for somthing other than growing grass.  Too bad we finsihed so late in the season, since I thought the gardening would be what I enjoyed most.  I'm looking forward to next Spring.  I have been reading posts on the two major large scale railroad websites, and hopefilly utilized many of the suggested best practices.  However, it seems this track expansion problem post was a little late for me since all the track is now down.  If I need to install expansion joints, better this Winter than when it gets hot next summer!

 

As you requested, here are a few more photos of the "Tantarra Western Rail Road".  I'll post more after we get plants in place next spring.

Regards,

Jack

 

 

 

 

 

Jack,

 

The question that I had after looking at that picture was..  Would the "pinned" track have bowed if slip jointers were used?

If the ties are held in place and there are gaps between the rail; won't the rail expand length wise to fill the gap rather than bow?

That's sort of how the expansion track works, right? 

 

 

Yes, assumming the expansion track can absorb the amount of expansion that occurs when the track heats up in the sun and not pull apart with too much contraction when the rail cools when the sun goes down.

 

Another problem is that if more than one  expansion section is employed, the rail must be rigidly fixed in place in the center of the length of rail.  Otherwise, the rail may work its way to one end in repeated expansion and contraction cycles.  i.e.: it expands into the expansion section on both ends, but when it contracts again whichever expansion section has the least friction will pull to the widest point, effectively moving the track to the other end.

I put a dime's thickness in all my track joints for expansion.  Worked great on the first expansion, but since my track is fully floating when it again contracted all the joints held except one and it then became about 10 dime's thickness wide and thus came apart since the joiners are only about 5 dime thicknesses long!

 

 

I'm now wondering how - or if - 1:1 railroads handle this problem.

 

The German ICE trains (and probably other high-speed trains as well) use continuously welded rails attached to solid concrete ties and roadbed. Here's a description of roadbed construction:

 

"The entire roadbed is made from reinforced concrete. The ground is leveled and prepared, and a concrete bed at least a foot thick is laid on it. This is the sub-bed for the track proper. Next, a mesh of steel rebars is placed on the sub-bed, and 'ties' - pairs of concrete rail anchor blocks (ready to use) connected in gauge by separate rebar clusters - are placed over the mesh. The whole mass is then set in concrete, about 16" thick. Except for gravel berms along the sides of the roadbed, the entire arrangement is monolithic."

 

Any ideas on how this contrained system overcomes expansion?

Greg,

 

Thanks for the tip on Split Jaw expansion clamps. 

 

I elected to go with the Split Jaw expansion rails instead.  I noted someting else on thier website which explained that in order for the rails to expand freely, the small screws which hold the tie sections to the bottom of the rails must be removed on all non-flex track.  Wow, if I had only known about the expansion problems before I screwed down all the track to the ladder system track bed.  This looks like several weekends of removing ballast, unscrewing track, removing the tie/rail screws, reclamping the track, rescrewing the ties back to the roadbed ladder material, installing the six sections of Split Jaw SS expansion track into all the longer streight sections, and re-ballasting.  I also need to work on the curves by removing as many screws as possible, while still keeping the track on top of the roadbed.  I now realize why some of the ties have center slotted holes... so that curved tracks can move back and forth as they expand and contract without the rail tearing out the screw secured ties.  To do it right, I'll have to take up all track except within the tunnels, which hopefully have some resistance to large movement since they are not in the sun and are only suseptable to actual temperature changes. 

 

Now when is it that the fun starts...???   

One think to keep in mind that anchors are only part of the process of controlling rail movement.  The screw that hold your rail to the ties in reality are rail anchors  Also you have a void under the ties to collect the ballast and also helps restrain the track.   Ballast isa key factor.  RR make sure they have a full crib of ballast and at least 12 inches on either side of the ties then the shoulder based on a 2 to 1 slope.  You need the 12 inches of ballast on either side of the ties to keep the track from moving laterally.  

 

I have almost a 100  % temp change in our areaduring the year.   My track is free floating and has been down for over 5 years.  No sunkinks as yet.  My rail is laid as the 1 to 1 rails lay theirs so the theory  works even in scale RR-ing.  Later RJD

Greg,

 

You seem pretty knowledgeable, can you give us a more in depth explanation on how this is supposed to work?

 

Regards,

pk